Public data register
Calculator assumptions
Calculator model assumptions
The physical and financial modelling constants behind the solar, battery, EV, heat pump and boiler calculators.
Provenance
Provenance documented
- What it is
- The physical and financial modelling constants behind the solar, battery, EV, heat pump and boiler calculators.
- How it is produced
- Maintained editorial figure
- Source
- PowerGuardian modelling assumptions, documented per tool
- Coverage
- United Kingdom
- Period
- Reviewed alongside each tool
- Last verified
- Not recorded
- Update cadence
- Reviewed when a tool is updated
- Where it lives
src/data/solarPaybackAssumptions.ts, batteryRoiAssumptions.ts, evChargingAssumptions.ts, heatPumpAssumptions.ts, boilerAssumptions.ts- Delivered by
- Held in the codebase registry
How the figure is produced
- Each tool has one assumptions module holding its constants — yields, efficiencies, degradation, lifetimes, discount rates and installation cost bands.
- Assumptions are exposed on the tool page so a reader can see, and usually change, what drove the result.
- Shared figures such as consumption and fuel prices are imported from the central registries rather than restated per tool.
The data
| Tool | Assumptions module |
|---|---|
| Solar payback calculator | src/data/solarPaybackAssumptions.ts |
| Battery ROI calculator | src/data/batteryRoiAssumptions.ts |
| EV charging cost calculator | src/data/evChargingAssumptions.ts |
| Heat pump running cost calculator | src/data/heatPumpAssumptions.ts |
| Boiler cost calculator | src/data/boilerAssumptions.ts |
- PowerGuardian public data register — calculator model assumptions
- Each tool page publishes its own assumptions in full, including the values a reader can change.
- Outputs are illustrations, not quotations.
What this figure cannot tell you
- Every output is an illustration. Real quotes, installation conditions and usage patterns move results materially.
- Financial assumptions such as inflation and discount rates are judgements, not forecasts.
- Installation cost bands are indicative ranges, not quotations.
Where it is published
Related records
- Illustrative fuel prices and heat pump efficiency — The shared UK-average pence-per-kWh prices and typical heat pump performance factor used across the tools.
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